Method for cooling granular solid materials, and continuous curing facility as such

Abstract

Method for cooling granular solid materials from a continuous curing facility having at least one area for burning a fuel to cure granular materials, wherein the curing of the granular materials, then the cooling of the cured granular materials is carried out in two consecutive steps, a first cooling step in a first cooler and a second cooling step in a second cooler, the method including: providing a cold air source for cooling the granular materials, the cold air source directly supplying air to the second cooler by blowing, and the air heated by the cured granular materials being used during the cooling as combustion gas for the burning area. All gases generated by the first and second coolers are routed to the burning area for use as a combustion gas, and the amount of cold air blown to the second cooler is adjusted to cover the air combustion needs.

The invention claimed is: 
     
       1. Method of cooling granular materials coming from a continuous curing facility ( 1 ), having at least one area for burning ( 41 ,  42 ) a fuel for the curing of the granular materials, wherein is carried out the curing of the granular materials in said facility then the cooling of said cured granular materials in two consecutive steps, a first cooling step implemented in a first cooler ( 2 ) of the facility and a second cooling step implemented in a second cooler ( 3 ) of the facility, method wherein:
 a cold air source ( 31 ) is provided for the cooling of the granular materials, said cold air source ( 31 ) supplying directly said second cooler ( 3 ) by air blowing, 
 the air heated by the cured granular materials, during the cooling, is used as combustion gas for said at least one area for burning ( 41 ,  42 ) of the facility ( 1 ),characterized in that: 
 the totality of the gases ( 133 ,  134 ;  222 ,  234 ;  334 ,  335 ) generated by said first cooler ( 2 ) and said second cooler ( 3 ) are routed towards said at least one area for burning ( 41 ,  42 ) of said curing facility in order to be used as combustion gas, without filtration of said gases, 
 the quantity of cold air ( 31 ) blown to said second cooler ( 3 ) is adjusted in such a way as to cover but not excessively the air combustion needs of said facility ( 1 ). 
 
     
     
       2. Method according to  claim 1 , wherein the first cooler is a tubular cooler, said second cooler a grate cooler. 
     
     
       3. Method according to  claim 1 , wherein the temperature of the granular materials ( 54 ) at the output of said second cooler ( 3 ) is controlled and the temperature of the materials ( 53 ) at the output of the first cooler ( 2 ) is controlled, by the intermediary of an exchanger ( 6 ), and the temperature of the air exiting ( 132 ) from the second cooler ( 3 ) is lowered by means of said exchanger ( 6 ) before introducing the air cooled ( 121 ) by said exchanger ( 6 ) into said first cooler ( 2 ), as cooling air. 
     
     
       4. Method according to  claim 3  wherein the air exiting ( 132 ) from the second cooler ( 3 ) is used in totality as cooling air of the first cooler ( 2 ). 
     
     
       5. Method according to  claim 1 , wherein the temperature of the granular materials ( 54 ) at the output of the second cooler ( 3 ) is controlled by injection of water in the first cooler ( 2 ) and the evaporation water injected ( 70 ) into said first cooler ( 2 ). 
     
     
       6. Method according to  claim 5 , wherein the temperature of the granular materials at the output of said first cooler ( 2 ) is determined by the adjusting of the flow of injected water ( 70 ). 
     
     
       7. Method according to  claim 5 , wherein, in addition to the injected water ( 70 ), the cooling fluid to the first cooler ( 2 ) is constituted by a portion ( 211 ) of the air exiting from said second cooler ( 3 ). 
     
     
       8. Method according to  claim 5 , wherein the injected water ( 70 ) constitutes the only cooling fluid used in the first cooling step to said first cooler ( 2 ). 
     
     
       9. Method according to  claim 8 , wherein the evaporated water ( 71 ) of said first cooler ( 2 ) is mixed with a portion ( 333 ) at least of the heated air exiting from said second cooler ( 3 ) before using the wet air mixture ( 335 ) as combustion air in said facility ( 1 ). 
     
     
       10. Method according to  claim 2 , wherein the temperature of the granular materials ( 54 ) at the output of said second cooler ( 3 ) is controlled and the temperature of the materials ( 53 ) at the output of the first cooler ( 2 ) is controlled, by the intermediary of an exchanger ( 6 ), and the temperature of the air exiting ( 132 ) from the second cooler ( 3 ) is lowered by means of said exchanger ( 6 ) before introducing the air cooled ( 121 ) by said exchanger ( 6 ) into said first cooler ( 2 ), as cooling air. 
     
     
       11. Method according to  claim 2 , wherein the temperature of the granular materials ( 54 ) at the output of the second cooler ( 3 ) is controlled by injection of water in the first cooler ( 2 ) and the evaporation water injected ( 70 ) into said first cooler ( 2 ). 
     
     
       12. Method according to  claim 6 , wherein, in addition to the injected water ( 70 ), the cooling fluid to the first cooler ( 2 ) is constituted by a portion ( 211 ) of the air exiting from said second cooler ( 3 ). 
     
     
       13. Method according to  claim 6 , wherein the injected water ( 70 ) constitutes the only cooling fluid used in the first cooling step to said first cooler ( 2 ). 
     
     
       14. Continuous curing or calcination facility ( 1 ) having least one area for burning ( 41 ,  42 ) a fuel for the curing of the granular materials wherein the granular materials are cooled in two consecutive steps, a first cooling step implemented in a first cooler ( 2 ) of the facility and a second cooling step implemented in a second cooler ( 3 ) of the facility, said installation ( 1 ) having a cold air source ( 31 ) for the cooling of the materials supplying directly said second cooler ( 3 ) characterized in that it has:
 gas ducts making it possible to route the totality of the hot gases generated ( 133 ,  134 ;  222 ,  234 ;  334 ,  335 ) by said first cooler ( 2 ) and said second cooler ( 3 ) towards said at least one area for burning ( 41 ,  42 ) of said facility ( 1 ), without filtration of said gases, 
 means for adjusting the quantity of cold air blown to said second cooler ( 3 ) in such a way as to cover but not excessively the air combustion needs of said facility. 
 
     
     
       15. Installation according to  claim 14 , wherein the first cooler is a tubular cooler, said second cooler a grate cooler, supplied by the cold air source ( 31 ). 
     
     
       16. Installation according to  claim 14 , having an exchanger ( 6 ) able to allow for the control, and even the adjusting of the temperature of the granular materials at the output of said second cooler ( 3 ), said exchanger ( 6 ) making it possible to cool the gases ( 132 ) exiting from said second cooler ( 3 ) before using the gases ( 121 ) cooled by the exchanger ( 6 ) to said first cooler ( 2 ) as cooling air. 
     
     
       17. Installation according to  claim 14  having means ( 7 ) for injecting water into said first cooler ( 2 ) able to allow for the control, and even the adjusting of the temperature of the granular materials at the output of said second cooler ( 3 ). 
     
     
       18. Installation according to  claim 15 , having an exchanger ( 6 ) able to allow for the control, and even the adjusting of the temperature of the granular materials at the output of said second cooler ( 3 ), said exchanger ( 6 ) making it possible to cool the gases ( 132 ) exiting from said second cooler ( 3 ) before using the gases ( 121 ) cooled by the exchanger ( 6 ) to said first cooler ( 2 ) as cooling air. 
     
     
       19. Installation according to  claim 15  having means ( 7 ) for injecting water into said first cooler ( 2 ) able to allow for the control, and even the adjusting of the temperature of the granular materials at the output of said second cooler ( 3 ). 
     
     
       20. Installation according to  claim 16  having means ( 7 ) for injecting water into said first cooler ( 2 ) able to allow for the control, and even the adjusting of the temperature of the granular materials at the output of said second cooler ( 3 ).